FLEX is an macro recorder which can remember shortcuts to control Nuendo. It helps to reduce the hand strain associated with the use of a mouse, and it can execute frequently used commands with a single button press.

There are simply not enough key combinations availble to use all of the commands in Nuendo. Or you have to use some weird combinations, like Ctrl + Alt + Shift + key. For example, Nuendo 2 introduced 14 new shuttle commands. Immagine that you would need to press such a key combination just to shuttle audio.

Here enters FLEX. You could use all those difficult shorcut combinations to trigger commands of your choice, and still use your computer keyboard to input commands that you already know and use. Flex, or any other macro keyboard, could be an extension of the computer keyboard, with big, colored and clearly labeled functions.

FLEX is not available anymore, but in my opinion the idea is still valid and similar products are being introduced. See the latest example here.